Will steel angle work for a decent machine?

[routercnc]

I wouldn't like to say for sure on electrical bits but comparing what you have with popular steppers for general CNC work:
.
Yours.....vs...Typical (e.g. SY60STH86-3008BF)
1.9 Nm..........3 Nm
2.8 V............5.46 V
78 mm..........88 mm
?.................3.2 mH (inductance - important value to get right)
3 A..............4.2 A
.
I have a stepper close to your spec on the Z and it works OK but I wouldn't use it on the X or Y (gantry) as it's a bit low on torque etc. M60STH88-3008DF is another popular choice with a similar spec. I'm giving you this info so you can build up your library of knowledge and have a look around - don't buy these sorts of bits yet until the design is ready!